Coresight: Add Coresight TMC Control Unit driver

The Coresight TMC Control Unit hosts miscellaneous configuration registers
which control various features related to TMC ETR sink.

Based on the trace ID, which is programmed in the related CTCU ATID
register of a specific ETR, trace data with that trace ID gets into
the ETR buffer, while other trace data gets dropped.

Enabling source device sets one bit of the ATID register based on
source device's trace ID.
Disabling source device resets the bit according to the source
device's trace ID.

Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Jie Gan <quic_jiegan@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250303032931.2500935-10-quic_jiegan@quicinc.com